Usually discussions about manager are about strategy. With the way baseball is played today, especially in the American League, strategy doesn't mean much unless Forrest Gump, I mean Grady Little, is managing your team. More important to the success of managers is how he manages his players (hence the name manager), and especially if managers can maximize the talent of each player.
One reason Joe Torre and Terry Francona are successful managers is that they're patient and loyal. This patience and loyalty is more important than daily strategy. All manager, except for Grady Little, are competent with game strategy. Not all managers are patient with their players.
Maybe the best example of Francona's patience leading to success is how he handled Mark Bellhorn last postseason. Bellhorn was horrible in the beginning of the playoffs, and everyone, including me, wanted him benched. Francona stuck with Bellhorn and Bellhorn's hitting helped the Sox win Games Six and Seven against the Yankees.
Being patient works on at least two levels. One, players usually do get out of slumps, so they will eventually deliver. Two, players see that their manager believes in them, so the clubhouse gets a good atmosphere and players want to perform well for managers who support them.
Here's two problems with patience:player who don't get out of a slump and restless fans and owners. It was reported a while ago that George Steinbrenner was upset that Torre didn't want any drastic changes to his team. Terry Francona has some leverage with Boston fans because of his ring, but fans are getting restless with his loyalty to Bellhorn, Foulke, and Millar (even though he's improving now).
Torre and Francona are secure enough with their jobs that they're not worried about being fired. Torre might actually welcome it. It's the managers who don't have job security who must find it tougher to stick with players through a slump. A manager's patience is usually good for the player's development, but it can also get the manager fired.
So, what does Francona do about Keith Foulke?